The Coultershaw Trust has been given a £30,000 lottery boost to aid its £267,000 restoration plans on the site close to Petworth which is home to the historic beam pump.
The Coultershaw pump, which celebrated 30 years of opening to the public in July last year, is waterwheel-driven and was installed in 1782 to pump water from the River Rother to Petworth, some 1.5 miles away and 150 feet higher.
It was restored by the Sussex Industrial Archaeology Society with the aid of grants from the department of the environment and West Sussex County Council.
The machinery was returned to working order and a 100-year-old barn from Goodwood erected over it to act as a reception and display centre, and the pump is now a scheduled ancient monument.
The Coultershaw Trust, which is responsible for the care of the site, has now made a successful bid to the Heritage Lottery fund for a grant of up to £30,100 towards the cost of restoring two more buildings at Coultershaw.
Chairman of the trust Robin Wilson said: “It is proposed to restore part of a 19th-century warehouse as an education room with toilets and the engine house as a gallery for George Garland photographs.
“Improved access will be provided by a new footbridge across the river and a boardwalk connecting to the Rother Navigation.
“The proposals are in the context of the conservation management plan funded by the Heritage Lottery fund in 2007.
“The development work also includes working up details of the capital programme, including fit-out plans and the refurbishment of the pump house, and the development of an activity plan to improve the presentation of the historic site and the learning and participation opportunities for visitors.”
The trust also intends to carry out surveys on the feasibility of arranging school and special interest group visits.
A second application for a further grant will be made at the end of the year.
The trust is currently installing a 15kW Archimedean Screw water turbine in the wheel pit of the old corn mill, funded by the Leconfield Estates and grants from the former South Downs Joint Committee.